HDMI vs DisplayPort: What’s Missing?

HDMI does not support daisy-chaining multiple monitors from a single port, a feature unique to DisplayPort (and USB-C with DisplayPort Alt Mode). While both carry high-resolution video and audio, DisplayPort’s Multi-Stream Transport (MST) lets you run two to four displays from one output, something HDMI cannot do without a splitter or dock. This article explains that difference, how each connector handles bandwidth, refresh rates, and compatibility, and what to check before buying cables or monitors.

Background: Why Two Standards?

HDMI was developed in 2002 by consumer electronics companies (Hitachi, Panasonic, Philips, Silicon Image, Sony, Thomson, Toshiba) to replace analog composite and component cables. It was designed for TVs, projectors, and home theater gear, with a focus on plug-and-play simplicity and copy protection (HDCP). DisplayPort arrived in 2006, created by VESA (Video Electronics Standards Association), primarily for computer monitors and graphics cards. It was built with PC use in mind, offering higher bandwidth, packetized data transmission, and support for daisy-chaining.

Because of these origins, HDMI dominates consumer TVs and streaming devices, while DisplayPort is common on gaming monitors and professional displays. Most modern graphics cards include both, but laptops and ultrabooks often only have HDMI or USB-C (which can carry DisplayPort signals).

How HDMI and DisplayPort Differ

The core difference lies in how they transmit data. HDMI uses a fixed pixel clock and streams video line-by-line, similar to older analog signals but digital. DisplayPort uses packetized data, like Ethernet or USB, which allows multiple video streams to share one cable. That packetized design is what enables MST (Multi-Stream Transport) – the ability to send different images to several monitors through a single DisplayPort output.

Other key differences:

• Daisy-chaining: DisplayPort 1.2 and later support MST, allowing up to 4 monitors at 1080p or 2 at 4K from one port. HDMI has no equivalent; you need an external splitter that duplicates the same signal, not extends it.
• Audio return channel: HDMI has ARC/eARC to send audio from the TV back to a soundbar or receiver. DisplayPort also carries audio, but ARC is a TV-centric feature HDMI handles better.
• Connector size: DisplayPort has a latching connector that is harder to pull out accidentally, while HDMI is smaller and more common on thin devices. Mini DisplayPort exists but is less common now.
• Licensing: HDMI requires manufacturers to pay a royalty, which is one reason some budget devices use DisplayPort or USB-C instead. DisplayPort is royalty-free, though VESA membership costs.

Bandwidth and Resolution Support

Both standards have evolved over the years. HDMI versions: 1.4 (10.2 Gbps, 4K30), 2.0 (18 Gbps, 4K60), 2.1 (48 Gbps, 8K60 or 4K120 with HDR). DisplayPort versions: 1.2 (21.6 Gbps, 4K60), 1.3/1.4 (32.4 Gbps, 4K120 or 8K30), 2.0/2.1 (up to 80 Gbps, 16K with compression).

For most users, the practical difference is:

• HDMI 2.1 is required for 4K120 on modern gaming consoles (PS5, Xbox Series X).
• DisplayPort 1.4 is common on 1440p/240Hz and 4K/144Hz gaming monitors.
• DisplayPort 2.0 is still rare; most monitors use 1.4.

Note that HDMI 2.1 cables are often marketed as “Ultra High Speed” and are needed for full bandwidth. Older HDMI cables may not support 4K120, causing flicker or no signal.

Common Misconceptions

“HDMI is better for TVs, DisplayPort for monitors” – That’s generally true, but not a hard rule. Many TVs now have DisplayPort inputs (especially high-end models), and many monitors have HDMI. The key is matching the port version to the resolution/refresh rate you need.

“You can convert HDMI to DisplayPort with a simple adapter” – Not always. A passive adapter only works if the source outputs a DisplayPort signal (e.g., USB-C to HDMI). Going from HDMI to DisplayPort requires an active converter that includes a chip, because HDMI doesn’t carry the same signaling. These converters exist but cost more and may not support high refresh rates.

“DisplayPort is always better” – Not true. HDMI 2.1 has higher bandwidth than DisplayPort 1.4, and HDMI is required for features like VRR (Variable Refresh Rate) on some TVs and eARC for audio. For a PC gamer with a 1440p/240Hz monitor, DisplayPort 1.4 is ideal; for a home theater, HDMI 2.1 is the standard.

How to Choose the Right Cable or Port

Follow these steps:

1. Check your monitor’s native resolution and refresh rate (e.g., 3440×1440 at 100 Hz).
2. Check your graphics card or laptop’s available ports (HDMI version, DisplayPort version, USB-C with DP Alt Mode).
3. For daisy-chaining, you need a DisplayPort output that supports MST, and monitors with DisplayPort out ports (rare).
4. For console gaming, use HDMI 2.1 to get 4K120 with VRR.

If you’re buying cables, look for certification logos (e.g., HDMI “Ultra High Speed” or DisplayPort “DP40″/”DP80”). Cheap uncertified cables often fail at high bandwidth.

Frequently Asked Questions

Can I daisy-chain monitors with HDMI?

No, HDMI does not support MST. You can use a splitter to duplicate the same image, but not extend to multiple independent displays. For multi-monitor setups, use DisplayPort or USB-C with DisplayPort Alt Mode.

Is DisplayPort backward compatible with HDMI?

No, they use different signaling. You need an active adapter to convert from HDMI to DisplayPort, or a passive adapter from DisplayPort to HDMI (since DisplayPort can output HDMI signals with a simple cable).

Which is better for 4K gaming: HDMI 2.1 or DisplayPort 1.4?

For 4K/120Hz, HDMI 2.1 is required. DisplayPort 1.4 can do 4K120 only with Display Stream Compression (DSC), which is visually lossless but not supported on all monitors. HDMI 2.1 also supports VRR and eARC, making it the best choice for consoles and high-end TVs.

Why does my monitor only show 60 Hz over HDMI but 144 Hz over DisplayPort?

Your monitor’s HDMI port may be limited to an older version (e.g., HDMI 1.4) that doesn’t have enough bandwidth for high refresh rates. DisplayPort on the same monitor likely supports higher bandwidth. Check your monitor’s specs for the max refresh rate per port.

Can I use a USB-C to HDMI cable to connect a laptop to a TV?

Yes, if your laptop’s USB-C port supports DisplayPort Alt Mode (most do). The cable converts the DisplayPort signal to HDMI, so it works. However, if the USB-C port only supports USB data (no DP Alt Mode), you need an active adapter with a chip.

Does DisplayPort carry audio?

Yes, DisplayPort carries audio, but it’s less common on TVs. Most TVs don’t have DisplayPort inputs, so you’d need an adapter. For soundbars, HDMI ARC/eARC is the standard.

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